October 12, 2017

Just about everyone knows what a monarch butterfly is and its amazing migration to and from Mexico. But not nearly as many people have even heard of a painted lady butterfly; until this year that is. Reports of painted lady butterflies seem to be all over the twittersphere. The most popular one I’ve seen is the weather radar in Colorado picking up a huge swarm of the migrating butterflies.

In a garden that I tend, I’ve been seeing lots of painted ladies during the past couple of weeks. Although there’s many more than normal, they’re not in radar-detecting numbers, that’s for sure. Since it is the middle of October, most of the plants in the garden are done for the season. There are however, a couple of hundred late-planted zinnias still going strong. That seems to enough to convince the butterflies to stop by the garden to tank-up on zinnia nectar before continuing their journey south. I’ve noticed there is a wide size variation in the ones I’ve been seeing, some are only less than three-quarters the size of the larger ones. Apparently, the larger insects had much better feeding conditions when they were caterpillars than did their smaller companions.

Although not as big as monarchs, painted ladies are one of our larger butterflies.

A quick search online shows not much is known about this species compared to the the intensely studied monarch. They’re still figuring out how they find their way south and what triggers them to migrate. Unlike the monarchs that take more than one generation to migrate, the painted ladies make the entire trip as a single adult. They’re often found in their southern range all beat up from the long flight, yet they still search out just the right plants on which to lay their eggs.

All round the country the same thing is happening: a large expansion of the painted lady butterfly population. Some scientists are so impressed by some of the reports that they are comparing this rare event to this summer’s total eclipse. If you don’t want to be left out of what is possibly a once in a lifetime occurrence, find a place that still has a few flowers in bloom and take part in some fun butterfly viewing. You probably won’t see clouds of painted lady butterflies around here but you certainly won’t have to look very hard to find them.

You can find some really amazing things in the garden if you know where to look. For example, look closely at a salvia flower and you will see something unique.

Like most flowers, salvia produces nectar to lure pollinators such as wild bees, honeybees and others. And as usual the pollinators end up carrying pollen it picked up from the first flower to the next flower it visits thereby pollinating the second flower and others after that. Usually nectar collection is pretty straight forward, the bee simply visits the flower and sucks out the nectar and moves on to the next flower.

In the case of salvia however, something marvelous happens. The flower has a tiny structure that blocks access to the nectar. Instead if simply inserting its tongue and sucking out the nectar, the pollinator has to physically push itself deeper into the flower past the blockage in order to get to the nectar. That tiny gate that is hindering the bee is connected to the flower’s stamens by way of a pivot point like a see-saw. At the other end of the see-saw are a pair of stamens. At the very end of each stamens is a pollen sac.

Use a pencil to mimic the pushing behavior of a bee inside the flower and watch the stamens move.

When the pollinator pushes against the blocking structure, it causes the stamens to pivot downward. As the stamen moves down and touches the pollinator’s back, pollen is released from the pollen sacs onto the insect. The pollen sticks to that spot on the insect and once it is done gathering nectar, it moves on to other salvia flowers carrying the pollen with it.

All salvias have this astonishing mechanism in their flowers. Different species of salvia have slightly different lengths,sizes and shape of stamens. Some scientists believe that the different lengths of stamen by species minimizes hybridization ie. the pollination of two different species with one another. One type of salvia may deposit its pollen toward the rear of the insect while another may deposit at the front thereby reducing the mixing of pollen.

We’re nearing the end of the growing season but there are still some salvias blooming.